The present invention relates to an imprinting device for transferring a predetermined pattern of protrusions and recesses on a transfer target substrate such as a magnetic recording medium.
With increasing recording density of magnetic recording media, some magnetic recording media have been proposed for avoiding a problem of excessive recording referred to as side fringe. An example of this is disclosed in Patent Document 3 (see below). This proposed media include a magnetic recording medium with a discrete track structure having a groove between adjacent recording tracks and a patterned medium with dots each constituting one recording bit on a disk directed to achieving a higher recording density.
Utilization of nano imprinting technology has been proposed for manufacturing the magnetic recording media as disclosed in Patent Document 1 and Patent Document 2 (see below), for example.
An imprinting device for manufacturing magnetic recording media utilizing this nano imprinting technology comprises, as disclosed in Patent Document 2 for example, principal construction elements comprising a press bottom plate with a substrate-mounting surface on which a substrate having a resist film is disposed and a press top plate, which is disposed immediately adjacent to or separated from the press bottom plate with a disk-shaped stamper. This stamper has a pattern of recesses and protrusions to be transferred on its central region. A known example comprises a buffer sheet between a stamper and a press top plate to unify the pressing force.
In manufacturing a discrete track medium or a patterned medium using the above imprinting device construction, an original die of a stamper (or a mould) having a fine pattern of recesses and protrusions formed on a transferring surface thereof, is used for transferring the pattern onto a surface of a magnetic disk substrate using a resist resin coating. Then, an etching process is carried out using the resist film with the transferred pattern of recesses and protrusions as a mask, to provided a magnetic layer on the medium (a magnetic disk) having the pattern of recesses and protrusions.
When the pattern of recesses and protrusions is transferred on one surface of a substrate, the substrate is positioned on a substrate-mounting surface by inserting a positioning cylinder (a positioning pin), provided on the press bottom plate, into a through hole provided in the center of the substrate. When the pattern of recesses and protrusions is transferred onto both surfaces of a substrate, the substrate is placed on a substrate-mounting surface of the press bottom plate with the both surfaces being sandwiched by two stampers. As in the case of transferring to one surface, the substrate is positioned on the substrate mounting surface by inserting a positioning cylinder provided on the press bottom plate into the central through-hole of the substrate.
[Patent Document 1]
    Japanese Unexamined Patent Application Publication No. 2006-326927[Patent Document 2]    Japanese Unexamined Patent Application Publication No. 2005-108351[Patent Document 3]    Japanese Unexamined Patent Application Publication No. 2005-056535
The printing devices as described above, however, have the following problems during mass production. Firstly, in every imprinting job, the substrate, the stamper, and the buffer sheet must be sequentially inserted and assembled, and removed in the reverse sequence. Therefore, a reduction in the cycle time is difficult and complex manipulation is required. Secondly, in the processes of assembling and removal, friction with the positioning pin generates dust which tends to produce transfer defects.
It is therefore an object of the present invention to provide an imprinting device which achieve a short cycle time and generates scarce transfer defects without requiring complex manipulation.
Further objects and advantages of the invention will be apparent from the following description of the invention.